Noise Cancelling or In-Ear Isolation

I fly a glider which uses a very noisy engine to take off which takes about 5 minutes and then the engine is turned off for the rest of the flight. I therefore need a light Noise Cancelling or In Ear Isolating headset. I have been using a pair of Sennheiser PX250 which work but do not resally have the power to cancel all the noise and tend to distort the voice of the flight controller which is the whole reason for having the phones on the first place.

The noise we are talking about is like listening to a car engine being revved up with the bonnet open.

What is the best set for noise removal (Passive or active)?

I am not interested in the sound quality provided the voice of the controller is clear.

I prefer passive noise cancelling - no batteries! - With your, very particular, application I would think that smaller in ears would be the least intrusive option. You may feel differently and I could also see a pair of the full size, over ear Beyer DT770 working as an excellent pair of ear muffs. The trouble with larger earphones (apart from the size) is that better isolation will come with the more expensive studio type whereas in ears should cut down the noise nearly as much, especially with Comply Foam Tips.

You will never get rid of this noise entirely, especially as it sounds like you are pretty much strapped to this little engine, you will always perceive the vibration and low end noise but decent in ears - with no sound port - Would have a good chance at making it more than bearable.